Large Ziploc baggies work great for assembling stuff for your layout. Use one baggie per layout. Pack the papers you think you will use but have a back up piece or two. Punches, stickles (always remember they take time to dry so Stickle early in the day! Ribbon, Ink. Go thru your stamps first and pick out the ones specific to the layout. Some plain colored brads can be painted to whatever color you need that day. A few generic background stamps usually come in handy.
Trimmer, Adhesive and Scissors are a must!
Above all have fun!